A variety of fire escape devices are known. Many of these devices utilize a rope that is wound about a pulley mechanism. The pulley mechanism provides a resistive force so that the rate of descent of the passenger may be controlled by hand.
Examples of such devices may be seen in the following U.S. Pat. Nos.: 1,128,025 (Mass); 1,351,734 (Barrington); 2,432,741 (Frankel); and 4,550,801 (Forrest).
Most of the devices described in the above patents are quite cumbersome and thus are not practical as devices that may be inconspicuously stored and easily retrieved in case of an emergency. It is desirable that a fire escape device be less cumbersome so that it is not considered an eyesore or an obstruction in the home. There is also a tendency in the above devices for the rope to wrap onto itself and tangle or bind so that the passenger may become stuck before reaching a point of safety. Finally, the above devices provide little to ensure that the passenger is balanced in a generally upright position when they are being lowered. Since the rope is typically only attached at the point of descent, it will tend to be unsteady and sway when a person is being lowered along it. Consequently, it is highly desirable that the passenger be comfortably balanced when they are being lowered so that their descent is not hindered by their disorientation. If the passenger is responsible for regulating their own rate of descent, it is imperative that they be in a comfortable balanced position.
Some of the above problems have been addressed to a certain extent by U.S. Pat. Nos. 518,920 (Harvey) and 4,598,793 (Lew et al.), which provide escape devices featuring grooves in the pulley mechanism for accommodating the rope. The grooves guide the rope about the pulley and thus reduce the chances of the rope becoming tangled or binding.
The Lew at al. patent provides a cumbersome device however which is impractical to store or set up. The Harvey patent, on the other hand, provides a relatively portable unit. In this device, the pulley is further enclosed by a cylindrical body having apertures aligned in a vertical position allowing the rope to be fed through the pulley. The Harvey device does not provide adequate balancing means however, and indeed the device appears to have a tendency to pivot under the weight of the passenger being lowered. The pivoting of the device could place the passenger in a precarious position dangling from the harness. Furthermore, the apertures would likely no longer be vertically aligned and the rope may not feed properly through the pulley means. Thus the descent of the passenger may be severely retarded or even stopped. Finally, the cylindrical body is not so spaced from the pulley as to ensure that the rope will not ride out of its groove and become tangled upon itself.
It is desirable to provide an improved fire escape device that addresses the problems faced by the above prior art devices. The device should be reasonably portable so that it may be stored in a place near an escape route, such as a window. It should provide means to reduce the chances of the rope becoming tangled or binding. Finally the device should ensure that the passenger is comfortable and balanced when descending along the rope.